Oral melanoma and other pigmentations: when to biopsy?

Oral pigmentations (OPs) are often neglected, although a meticulous examination of the oral cavity is important not only in the diagnosis of oral melanoma, but also for the detection of important clinical findings that may indicate the presence of a systemic disease. OPs may be classified into two major groups on the basis of their clinical appearance: focal and diffuse pigmentations, even though this distinction may not appear so limpid in some cases. The former include amalgam tattoo, melanocytic nevi, melanoacanthoma and melanosis, while the latter include physiological/racial pigmentations, smoker's melanosis, drug-induced hyperpigmentations, postinflammatory hyperpigmentations and OPs associated with systemic diseases. We will discuss the most frequent OPs and the differential diagnosis with oral mucosal melanoma (OMM), underlining the most frequent lesions that need to undergo a bioptic examination and lesions that could be proposed for a sequential follow-up.